AAS Steroid Profile: Anabolic and Androgenic Ratings

In the world of anabolic androgenic steroids, the term “steroid profile” has two fundamentally different meanings.

For laboratories and anti-doping organizations, it refers to a set of metabolites in urine that allows for the detection of banned substances through an athlete’s biological passport.

For the practicing athlete and sports pharmacologist, a steroid profile is a comprehensive characteristic of a specific drug, describing its key properties: the ratio of anabolic to androgenic activity, its tendency to aromatize, its half-life, and its safety profile.

Understanding these parameters allows for the informed selection of steroids for specific goals, helps minimize side effects, and enables the construction of effective cycles.

Preface

The scientific community began to form the concept of the steroid profile back in the mid-20th century when the first modified forms of testosterone were synthesized. Researchers quickly discovered that minor changes in the chemical structure of a molecule could drastically alter its properties: some steroids became powerful stimulators of muscle growth with minimal masculinization, while others retained strong androgenic effects but produced less muscle gain.

By the 1980s, a system for evaluating drugs based on several key parameters had been established, and with minor changes, it is still used today. In laboratory settings, the steroid profile is studied using gas chromatography-mass spectrometry, which allows for the precise determination of the concentrations of various metabolites and their ratios.

For an athlete, a steroid profile becomes a roadmap, enabling them to predict how a drug will behave in the body.

1. Knowing that a particular steroid has high androgenic activity allows one to prepare in advance for possible side effects like acne or aggression.

2. Understanding the half-life helps to establish an injection schedule that maintains stable blood levels of the substance without sharp peaks and troughs.

3. An assessment of hepatotoxicity dictates the need to include liver protectants in the cycle and to limit the duration of oral administration.

Who Creates Steroid Profiles and How

Professional sports organizations, such as WADA, compile steroid profiles to create an athlete’s biological passport. In this context, the profile includes the measurement of indicators such as testosterone, epitestosterone, androsterone, etiocholanolone, and their ratios in urine. Regular monitoring allows for the detection of deviations from an individual’s norm, which may indicate the use of exogenous steroids. Research shows that the steroid profile depends on gender, age, physical activity, diet, and even ethnicity, which is why national reference value databases are created for the correct interpretation of results.

Pharmaceutical companies and research laboratories develop steroid profiles during the synthesis of new compounds.

• In controlled experiments on animals and, later, on humans, a drug’s bioavailability, its affinity for androgen receptors, its metabolic and excretion rates, and its range of side effects are studied.

• This data forms the basis for clinical recommendations and instructions for use.

• For anabolic steroids, originally developed as medications for anemia, osteoporosis, and muscular dystrophy, this approach ensured patient safety and predictable therapy.

In the bodybuilding community, the steroid profile is formed empirically, based on the multi-year experience of thousands of athletes:

• Parameters such as anabolic and androgenic activity are expressed as percentages relative to testosterone, which is taken as 100 percent.

• These figures are not derived from strict clinical trials but from analyzing user feedback, comparing results, and observing bodily reactions.

For example, Stanozolol has an anabolic index of about 320 percent with an androgenic index of only 30, making it a popular agent for cutting, whereas the androgenic activity of Trenbolone approaches 500 percent, explaining its powerful impact on strength and aggression.

Modern online databases allow any athlete to study the steroid profile of a drug of interest in minutes. A typical description includes the structural formula, trade names, recommended dosages, expected results, and a detailed list of side effects.

It’s important to understand here that this data is for reference purposes (remember, in the bodybuilding community, this data is obtained empirically) and should be used with caution, as individual reactions to steroids can vary significantly depending on genetics, lifestyle, and concomitant diseases.

Breakdown of Key Steroid Profile Parameters

When evaluating any anabolic steroid, a standard set of characteristics is used, allowing for comparison between drugs and prediction of their behavior.

We have listed the main parameters that need to be considered when planning a cycle:

• Anabolic Activity is the steroid’s ability to stimulate protein synthesis and muscle tissue growth. It is usually expressed as a percentage relative to testosterone, whose anabolic activity is conventionally set at 100 percent. The higher this indicator, the faster and more significant the muscle mass gain will be, all other things being equal. For example, Oxandrolone (Anavar) has an anabolic activity reaching 400 percent, making it very effective for gaining quality muscle with relatively low side effects.
• Androgenic Activity characterizes the steroid’s ability to cause masculinizing effects: voice deepening, growth of facial and body hair, acne, aggression, and stimulation of libido. High androgenic activity is desirable for increasing strength levels but poses risks for women and athletes prone to baldness or skin issues. For Trenbolone, this indicator can reach 500 percent, explaining its reputation as the most potent steroid for gaining lean mass, but also its high risk of androgenic side effects.
• Estrogenic Activity is associated with the steroid’s ability to convert into estrogens via the aromatase enzyme or to directly activate estrogen receptors. Drugs with high estrogenic activity, such as Methandienone, cause water retention, increase the risk of gynecomastia, and can lead to elevated blood pressure. Steroids not subject to aromatization, like Stanozolol or Trenbolone, are considered safer in this regard but require monitoring of the lipid profile.
• Half-Life determines how long the drug remains active in the body and how often it needs to be taken. For injectable steroids in ester forms, this period can range from several days to two weeks; for orals, from several hours to a day. Testosterone Enanthate has a half-life of about 4-5 days, allowing for weekly injections, while oral Methandienone requires daily intake, split into multiple doses, to maintain stable blood levels. Ignoring this parameter leads to an unstable hormonal environment and increased side effects.
• Toxicity, primarily hepatotoxicity, is critically important for assessing the safety of oral steroids. Many oral forms have a 17-alpha-alkyl group, protecting the molecule from breakdown in the liver but simultaneously placing a burden on this organ. Nandrolone and other injectable forms are significantly safer for the liver. Highly toxic steroids, such as Methyltestosterone or Oxymetholone, require short cycles, mandatory use of hepatoprotectants, and regular monitoring of liver enzymes.
• Impact on Libido is an important subjective indicator reflecting the steroid’s effect on sex drive and erectile function. Most androgens significantly increase libido during a cycle due to stimulation of androgen receptors in the central nervous system. However, after discontinuation, especially without proper post-cycle therapy, a sharp decline can occur, up to complete impotence, due to the suppression of natural testosterone production. Some drugs, like Trenbolone, can paradoxically lower libido in some athletes when taken in high doses.
• Impact on Blood Pressure is caused by several factors: water retention, increased circulating blood volume, stimulation of erythropoiesis, and direct effects on the vascular wall. Drugs with high estrogenic activity more frequently cause hypertension, while dry steroids have less impact on blood pressure. Long-term use of any anabolic without monitoring can lead to persistent arterial hypertension and left ventricular hypertrophy, requiring regular monitoring and, if necessary, correction with antihypertensive drugs.
• Impact on Lipid Profile is one of the most significant factors of long-term risk for the cardiovascular system. Most anabolic steroids lower high-density lipoproteins (good cholesterol) and raise low-density lipoproteins (bad cholesterol), as well as triglycerides. This atherogenic effect increases with higher doses and longer duration of use. Oral steroids, especially alkylated ones, have a more pronounced negative impact on lipids than injectables. Animal studies show that some supplements, like taurine, may partially prevent these changes, but it is impossible to completely negate them.
• Impact on Joints varies depending on the drug. Some steroids, such as Nandrolone, are known for their ability to reduce joint pain and improve collagen synthesis, which is associated with their effect on fibroblasts and fluid retention in connective tissue. Others, particularly drugs with high androgenic activity and a pronounced drying effect, can provoke brittleness in ligaments and tendons, creating a risk of injury during intense training. This parameter is important for athletes with musculoskeletal issues or those planning to work with maximum weights.
• Suppression of the Hypothalamic-Pituitary-Gonadal (HPG) Axis is the steroid’s ability to inhibit the production of natural testosterone through a negative feedback mechanism. The stronger the suppression, the longer and more difficult recovery will be post-cycle, and the more important proper post-cycle therapy becomes. This parameter varies among different drugs: some (e.g., Trenbolone) suppress the axis very strongly even in moderate doses, while others are more moderate.
• Impact on Hematocrit and Erythropoiesis is the ability to stimulate the production of red blood cells. This effect can be both beneficial (improving endurance and oxygen delivery) and dangerous (increasing blood viscosity, risk of thrombosis, stroke). Oxymetholone, for example, is known for its powerful erythropoietic action, which requires monitoring blood viscosity and possible blood donation.
• Receptor Binding Affinity is a parameter showing how strongly a drug binds to androgen receptors. High affinity means that even small doses produce a strong effect, but the risk of side effects also increases. Trenbolone has exceptionally high affinity, explaining its power at micro-doses.
• Anticatabolic Effect is the ability to suppress the breakdown of muscle tissue mediated by cortisol. This parameter is important when cutting and during strict diets. Many steroids possess this property, but its intensity varies.
• Progestogenic Activity is the ability of some steroids (especially 19-nor derivatives like Trenbolone and Nandrolone) to activate progesterone receptors. This can cause specific side effects, including libido suppression, increased prolactin, and a general feeling of being unwell.

Testosterone as the Reference Point

The choice of testosterone as the standard with a value of 100 is dictated by the history of endocrinology’s development.

• Testosterone was the first androgen isolated in its pure form (Ernst Laqueur, 1935), and it was its biological effects that became the starting point for studying the entire group of anabolic steroids.

• Scientists needed to create a coordinate system to compare newly synthesized compounds with the natural standard.

• Testosterone naturally became that “zero point” against which they measured how much stronger or weaker a substance was in its anabolic and androgenic action.

The methodology for fixing testosterone at 100 was established in the 1940s and 1950s thanks to the work of pharmacologists like Claudio Hershberger and his colleagues. They developed biological tests on animals (e.g., on rats and cockerels) that allowed for the quantitative assessment of androgenic activity (growth of seminal vesicles) and anabolic activity (increase in muscle mass, e.g., the musculus levator ani). The results for new steroids were expressed as a percentage of the effect obtained from administering testosterone to a control group. This firmly established testosterone as the reference point with a value of 100 for both parameters.

This scale proved convenient and clear: an anabolic index above 100 means the drug surpasses testosterone in its ability to build muscle tissue, while an androgenic index above 100 indicates it surpasses it in the intensity of male sex characteristics.

However, it is well worth understanding that these numbers are derived from animal experiments and do not always translate linearly to humans, but they remain an indispensable guide for comparing the properties of different steroids and predicting their effects.

Modern sports pharmacology still operates with these relative values, which originated in the pioneering research of the mid-20th century.